Laughing seizures due to a midline intraventricular neoplasm in tuberous sclerosis.

Laughing seizures have been described in association with hypothalamic hamartomas and precocious puberty. Laughing seizures due to a neoplasm arising from the floor of the left lateral ventricle extending down towards the hypothalamus in a child with tuberous sclerosis is reported. This combination has not been reported before and emphasises the importance of imaging to diagnose such midline lesions in children with paroxysmal laughing.